Making the Diagnosis
Doctors may consider a diagnosis of cyclothymia if there is a history of mood instability for a period of at least 2 years, and symptom-free intervals never last more than 2 months. For children and adolescents, symptoms only need to be present for a one-year period.
Cyclothymia will otherwise be difficult to diagnose if a person's mood instability has not been recognized and tracked over at least a couple of years. Because mood may be normal and stable for long periods of time - mood elevations or depressions can be quite mild - symptoms do not always attract medical attention. People may not look for help until symptoms and mood swings become severe enough to interrupt normal functioning and activities.
If a person has experienced major depressive, manic, or mixed episodes, the diagnosis will likely be changed to bipolar disorder. Your doctor will usually also need to rule out other conditions as these symptoms could be caused by substance abuse, physiological effects of certain medications, or an unrelated medical condition.